Method and apparatus for regenerating NOx adsorbers

Abstract

In a method of regenerating a NOx adsorber, the NOx adsorber is used to treat exhaust gases created during the combustion of gaseous fuels in general. Methane is introduced into a reformer or exhaust line in which hydrogen generated during reforming is used to regenerate the NOx absorber.

1. An aftertreatment system for treating NOx within exhaust gases produced during combustion of a fuel within a combustion chamber of an internal combustion engine system, the aftertreatment system comprising:
 (a) an exhaust line connected to carry exhaust gases from the combustion chamber to a NOx adsorber;
 (b) a reformer generating hydrogen and carbon monoxide from a gaseous hydrocarbon; 
 (c) an oxidizer reducing the oxygen concentration of a first quantity of air; 
 (d) a first gas line connected to deliver a first quantity of the gaseous hydrocarbon from a gaseous hydrocarbon store to the reformer; 
 (e) a regeneration line directing a regeneration mix into the exhaust line upstream of the NOx adsorber and downstream of the combustion chamber, the regeneration mix comprising the hydrogen and carbon monoxide from the reformer and the first quantity of air from the oxidizer, the reformer and the oxidizer disposed in the regeneration line; and 
 
 wherein an output of the oxidizer is connected to an input of the reformer and an output of the reformer is connected to the regeneration line. 
 
   
   
     2. The aftertreatment system of  claim 1  wherein the fuel is a gaseous fuel. 
   
   
     3. The aftertreatment system of  claim 2  wherein the gaseous fuel is directly injected into the combustion chamber. 
   
   
     4. The aftertreatment system of  claim 3  wherein the gaseous fuel comprises methane. 
   
   
     5. The aftertreatment system of  claim 4  wherein the gaseous fuel is directly injected into the combustion chamber. 
   
   
     6. The aftertreatment system of  claim 4  wherein the gaseous fuel comprises the gaseous hydrocarbon. 
   
   
     7. The aftertreatment system of  claim 6  wherein the gaseous fuel is directly injected into the combustion chamber.